An OrthographicPart is a unit of an orthography that is not orthographically independent, that is, not necessarily able to stand alone as an orthographic word set off by whitespace. In the printed instance of the word 'conceive', 'eive' is an instance of orthographic part. Note that an orthographic part is not the same as a single glyph, although, some orthogrpaphic parts are single glyphs.